<span class="highlight">BT50</span> Auto Transmission Cooling.

Also, dont tow in drive. Check your manual for correct gear.

My 200 series makes almost no difference between towing in drive and sports mode....it will very rarely shift into 6th, only downhill, so it will normally run in 5th (locked ) in drive or sports.

But different makes may do different, so as said , check the manual and find whats best for your 4wd, but don't take it as gospel !

Ron
I suppose you could call that distortion of solenoid bodies a "melt down". Defies logic why materials which soften to cause trouble are used in a Ford transmission. Is it to save a $, Hardly suitable for hot use. Is it not good if the auto selects two gear ratios at the one time?

RMD - We're talking Ford here - the masters of cost-cutting. They have bean-counters shaving 5c in build cost off every single part, that they can find, every day of the week.

They acquired the ZF transmission, and arranged to build it under licence.
But Ford never build anything the same as the original product, they have to cheapen everything in the construction. They've been that way for decades.

Cheers, Ron.

Ron, that problem has been fixed for a few years now, it only happened on some of the earlier ones.

I don't know where the 93 degrees came from as that is a pretty standard temp for the box.

The amount of workmine has done towing over the last 7 years, at temps well over 93 , it should be broken but to the contrary it is showing no problems at all. No burnt atf and no metal in the pan.

9900 Eagle - The link below provides some of the best auto tranny temperature advice I have seen.
You just need to do some F to C conversions and miles to kms conversions.

Tranny oil temperature advice

Temperature conversion

One has to keep in mind, that there are several different positions to measure tranny oil temperature, but the important place to measure, is the point where the oil is leaving the tranny.

And if the oil leaving the tranny is at 100 deg C, then internal components will be a lot hotter.

More good auto tranny and oil advice below, from the local experts.

The Transmission Centre - General tranny and oil info

Cheers, Ron.

Ron, I have seen all those before, in real life my fluid comes out as clean as with no sign of burning or deterioration at all, this is why I recommenced 60000k change when towing in my post. That has come from experience with this particular box.

That tranny oil temp advise is very old, and I would think it would even predate fully synthetic ATF.

Cougar - The modified tranny oil flow valve is offered and described in the link below.

Essentially, the factory flow valve restricts oil flow until the transmission is at operating temperature.

This is a design that caters for severe Nth American Winter conditions, where their low temperatures far exceed anything we get in Australia.

The factory flow restriction valve has a tendency to cause more problems than it cures, in our moderate climate.

Debris from bushings inside the transmission, plus small metal particles from general transmission wear, can stick in the factory flow restriction valve, and stop any oil from reaching the factory oil cooler.

The replacement valve is a full flow unit, which has no restriction at all. This also makes it easier to fill the transmission with oil and reach the correct oil level more quickly.

Fitting the full flow valve does mean the transmission takes a little longer to warm up - but in our climate, that should be of no concern - unless you live and work in high Australian Alpine regions on a constant basis.

Extremely cold oil makes for harsh shift changes in this transmission, thus the reason for Fords installation of the flow restriction valve, to ensure the tranny oil warmed rapidly in the depths of Nth American Winters.

Thermostatic bypass valve - Ford Ranger/Mazda BT-50 auto transmission

Cheers, Ron.

This link shows what should be going on with the box. It appears only 1st gear doesn't have TC lockup.
The link is more about the solenoid diagrams than the content. I hope you can get it sorted. TC's are all about pressure - maybe the extended system has upset it? I don't know. You can only be generating that much heat with an unlocked TC I'd guess?

https://gearsmagazine.com/magazine/updates-to-the-ford-6r80/

Maybe it is the Lock Up Clutch which is all about pressure, whereas the TC only works on being full of fluid. Applying pressure inside a TC only stresses the input seal. There is two entirely different systems inside the TC body/case.

Certainly the ZF equivalent in Landrovers lock the TC in first gear - but only when in low range so I guess it is a gearbox ECU thing rather than a gearbox issue but does highlight the TC can lock in first gear if it is programmed to do so.

The cost for the flow control bypass valve was $550.00 fitted, which also include new oil, filter and seal.

I had mine fitted by http://lenvossautomatics.com.au/

More info on the benefits of fitting the bypass valve here https://ronhillautomatics.com.au/bt50-and-ford-ranger-transmissions-need-extra-cooling/

Even if you didn’t have a Scangauge to monitor the temps I would recommend fitting the bypass valve, probably even before an after market cooler, although ideal to have an aftermarket transmission cooler.

Had a Superior transmissions Thermal Control Bypass valve fitted in January last year by Kennedy Automatics when a flush and filter change was being done to the auto. Cost of the part was $72.13.

It works well and there seems to be no effect on the gear shifting even with the lower temps.

One added bonus is if the original thermal valve fails like an engine thermostat can, it can't fail shut.

"Of some relevance is the instruction/advice contained in the BT 50 Owners manual about towing speeds if and when weights involved are greater than 3000kg.
It stipulates that if towing such weight then speed must not exceed 80kph. Refer page 153."

My 2014 BT50 handbook has the info on page 109 and the limit is 100kph if towing with a laden weight greater than 3000kg.

Interestingly, there are other restrictions that I bet most people have overlooked, such as decreased loads when towing at altitudes above 1000m and for gradients in excess of 12%